1. Field of the Invention
This invention relates to railway vehicles and in particular to a portion of the vehicle underframe where the so-called center sill interconnects with transversely extending bolster members and where the railway vehicle body is supported upon its wheeled truck.
2. Description of the Prior Art
As it is well known in the art, a railway vehicle is supported at each end by a member called a center plate unit which comprises a center plate member attached to the body portion of the vehicle and a bowl portion attached to a bolster of the supporting truck unit. Because the center plate is a relatively small member in proportion to the vertical and horizontal forces encountered by the railway vehicle during transit and during coupling and uncoupling, extremely high stresses are produced in this area of the railway vehicle which can result in premature or excessive maintenance. For years the railroad industry has thought to eliminate permature failures caused by stress cracking at this area of the railway vehicle by a number of different constructions. Prior arrangements included center plates attached to the horizontal flanges of the sill. However, it has been found that failures with such a construction can result when the spaced side webs of the center sill and horizontally extending flanges which extend therefrom, are not correctly aligned in a horizontal plane. Consequently, when a center plate mounting plate or a so-called sole plate is attached to interconnect the spaced side flanges of the center sill and the center plate is attached, in inaccurate alignment between the center plate and the truck mounted bowl results because of the mismatched surfaces. Therefore, when the center plate is not attached to a truly flat horizontal flange connecting mounting plate, it must be either machined flat to mate with the bowl portion of the supporting truck, or, there will be no full surface-to-surface contact and, instead, only a portion of the center plate will be in a very highly stressed condition resulting in tremendous forces being generated unevenly through the center plate, center filler, draft sill and bolster connection and oftentimes resulting in premature wear and failures.
Further, as rocking of the railway vehicle occurs during transit the outboard bevels permit car body pivoting about the bevel line rather than the edge type pivoting which would occur with a conventional center plate. After a limited amount of pivoting occurs about the bevel, the car side bearings would prevent further car body pivoting.
U.S. Pat. No. 2,178,034, Dorey, attempted to overcome the problem of mismatching the center sill flanges by providing a unitary center filler and center plate unit. However, Dorey, presents serious problems in its application because it does not disclose bevels or any manner of replacing a center plate which may be damaged and thus requires complete replacement of the entire center filler unit.
The Furniss, U.S. Pat. No. 3,703,239 (1972), shows a modular center filler with a separate center plate. However, the center filler does not provide a bottom plate protruding below the side flanges of the center sill. Thus, it is impossible to machine flat the mounting plate to which the center plate is attached. In the event there is a misalignment or mismatching between the center sill components the modular unit provided in Furniss will only reproduce the inaccuracies in the existing center sill construction.
On the other hand, applicant's invention overcomes the problems of the prior art by providing a modular unit that provides a mounting surface for a center plate that can be machined in the event additional flatness requirements must be met due to inaccuracies between the side members of the center sill. With the construction shown herein, the center plate is not attached to the sill flanges, thus further minimizing problems caused by flange misalignment. Further, because of the beveled edges, and the reinforcing plates aligned with the beveled edges, the forces encountered during rocking are evenly distributed into the center sill and bolsters.